Abstract: A solar cell that has a thin film of active material in which is defined a series or array of diffraction cells, wherein each diffraction unit-cell has a non-periodic series of diffraction features and is adapted to suppress at least one low order diffraction mode.

Abstract: An optical device including: a waveguide of refractive index na for carrying at least one mode of at least one wavelength, and at least one resonator with a resonant wavelength. The resonator has a mode volume of less than ten cubic resonant wavelengths. In use light in the waveguide is vertically coupled into the at least one resonator, and the waveguide and resonator(s) are arranged to provide wave-vector matching between at least one mode of the resonator and at least one mode of the waveguide.

Abstract: A solar cell that has a thin film of active material in which is defined a series or array of diffraction cells, wherein each diffraction unit-cell has a non-periodic series of diffraction features and is adapted to suppress at least one low order diffraction mode.

Abstract: An optical device including: a waveguide of refractive index na for carrying at least one mode of at least one wavelength, and at least one resonator with a resonant wavelength. The resonator has a mode volume of less than ten cubic resonant wavelengths. In use light in the waveguide is vertically coupled into the at least one resonator, and the waveguide and resonator(s) are arranged to provide wave-vector matching between at least one mode of the resonator and at least one mode of the waveguide.

Abstract: A monolithic device for the non-invasive measurement of optical parameters relating to a biological tissue comprising: at least one light emitter that emits light having a range of wavelengths and/or at least one detector for detecting light in a range of wavelengths transmitted or backscattered by the tissue, wherein one or more structures with sub-wavelength features is formed on the at least one emitter and/or the at least one detector.

Abstract: A system for non-invasive measurement of parameters relating to a biological tissue comprising: a plurality of light sources, each operable to emit a light signal with one or more predetermined wavelengths; a light detector for detecting light from the tissue as a result of illumination by the sources, and means for applying modulation functions to the light emitted to implement code division multiplexing, each source being associated with a different function, wherein the functions are selected so that there is substantially no cross correlation between them, and wherein the sources have overlapping spectra.